There are several vendors here. Go to the marketplace. TrentL probably has the cheapest ones currently, but he probably wont have it throughout the year for that price,
Jim Duffy at Refining Fire Chiles isolates his plants and grows in volume, but he is a little on the pricey side. You could also go to the creator Ed Currie at Puckerbutt, but his web site says he is currently sold out.